Bone status in nonambulant, epileptic, institutionalized youth. Improvement with vitamin D therapy

Vitamin D supplementation in children with epilepsy and intellectual disability

BACKGROUND

Children with epilepsy and intellectual disability have an increased risk of vitamin D deficiency. In this patient group, it is neither clear which factors are associated with the level of 25-hydroxyvitamin D nor what the therapeutic results are when Dutch guidelines are followed.

METHODS

This retrospective study included 30 patients who, in October 2012, were residents of the children's wards of a tertiary epilepsy center in The Netherlands (Kempenhaeghe). From November 2012 onward they received cholecalciferol supplementation in doses that met or exceeded Dutch guidelines. At baseline, after 6, and 15 months, serum 25-hydroxyvitamin D concentration was measured.

RESULTS

At baseline, the vitamin D status in 11 (36.7%) residents was found to be deficient, in 10 (33.3%) to be insufficient and in 9 (30.0%) sufficient. Supplementation dose, diet, body mass index, intellectual disability, and mobility were significantly associated with baseline 25-hydroxyvitamin D concentrations. The mean 25-hydroxyvitamin D concentration increased significantly from 57.40 ± 22.00 nmol/L at baseline to 89.47 ± 26.77 nmol/L after 15 months (P < 0.001). In spite of supplementation ranging from 400 to 1200 IU/day, 64% of the residents in the deficient category and 30% of those with an insufficient level at baseline failed to attain a sufficient vitamin D status after 15 months.

CONCLUSIONS

Not all residents reached a sufficient vitamin D status after supplementation at least equal to the amount recommended by the Dutch guidelines. In a high-risk population, such as our residents, we advise monitoring 25-hydroxyvitamin D concentrations, adjusting supplementation accordingly and following patients to ensure they reach sufficiency.

Bilateral femoral neck fractures secondary to chronic carbamazepine use treated by bilateral dynamic hip screw: A case report

INTRODUCTION

Bilateral femoral neck fractures without major trauma are rare and related to several conditions. Insufficiency fractures due to the use of anti-epileptic drug are one of the rare causes. This case study is about bilateral femoral neck insufficiency fractures resulting from chronic use of anti-epileptic drug.

PRESENTATION OF CASE

A 26-year-old woman was referred to our emergency department with a complaint of bilateral groin pain and a 12-year history of irregular carbamazepine use. The diagnosis was bilateral femoral neck insufficiency fractures due to irregular long-term carbamazepine use. One-stage bilateral dynamic hip screw osteosynthesis was performed. After 2 years of follow up, good result was obtained.

DISCUSSION

There are several risk factors for insufficiency fracture, and antiepileptic drug related osteoporosis is one of the reason. These drugs have negative effect on bone methabolism and bone mineral density.

CONCLUSION

To our knowledge, this is the first case in the literature of bilateral femoral neck insufficiency fracture due to chronic carbamazepine use. Joint and bone pain with a history of long-term use of anti-epileptic drug should be investigated carefully, and insufficiency fractures should be kept in mind.

Vitamin D deficiency in children with epilepsy: Do we need to detect and treat it?

Children and adolescents treated with antiepileptic drugs are known to have problems with bone metabolism, bone mineral density loss, and 2-3 times the fracture risk of healthy controls. We reviewed the literature regarding bone mineral density in children with epilepsy and vitamin D therapy in children treated with anti-epileptic drugs. Studies of bone mineral density markers in children with epilepsy have mostly found little significant difference in bone mineral density markers in children with epilepsy. They have been limited by small sample size and many of the studies have not corrected for confounding factors such as comorbidities, mobility, nutrition, and obesity. Studies of vitamin D therapy in children with epilepsy have shown little evidence of effect and have been similarly limited by lack of stratification with regard to confounding factors. There is a need for larger studies, using clinically significant outcomes such as fractures, including at risk populations such as symptomatic generalised epilepsy, impaired mobility, and polytherapy. At the present time in the absence of good evidence to the contrary, there remains concern that children with epilepsy are at risk of poor bone health and that vitamin D therapy may be beneficial. As low-dose vitamin D supplementation (400 IU per day) is now recommended for healthy children and it is biologically feasible that children with epilepsy may be at higher risk of clinically significant deficiency, it is important that neurologists ensure that low-dose vitamin D supplementation should be prescribed and compliance followed up in children with epilepsy.

Influences of bone and mineral metabolism in epilepsy

INTRODUCTION

Patients with epilepsy are at increased risk for metabolic bone disease, low bone mineral density and fractures.

AREAS COVERED

This article reviews the predictors and mechanisms of bone loss in patients with epilepsy. It provides information regarding the basic bone biology, evidences of osteopathy with epilepsy and the potential mechanisms of its pathogenesis. This review shows that long-term use of antiepileptic drugs (AEDs) is associated with the risk of osteopathy. However, age, gender, low body mass, severity of epilepsy, co-morbid conditions, institutionalization and calcium and vitamin D deficiencies are additional and modified risk factors. AEDs may indirectly accelerate bone loss through hypovitaminosis D, hypocalcemia and hyperparathyroidism or reduce bone accrual through decreasing the levels of calcitonin, growth factors and vitamin K. Also, AEDs may directly accelerate osteoclastic (bone loss) and/or reduce osteoblastic (bone formation) activities, the main cells involved in bone remodeling.

EXPERT OPINION

Understanding the basic bone biology and the pathophysiology of the disturbed bone and mineral metabolism in epilepsy will aid in identification and monitoring of patients at risk and in planning appropriate prophylactic and therapeutic measures.

Adverse effects of antiepileptic drugs on bone mineral density in children

Bone mineral content (BMC) or density (BMD) may be decreased in children with epilepsy either as a consequence of the epilepsy, the condition that caused the epilepsy or the treatment for epilepsy. This paper investigates the effects of antiepileptic drugs (AEDs) on BMD in children. A systematic search of Pubmed resulted in 14 papers that described changes in BMD in children on AEDs. For phenytoin, one study failed to show a decrease in femur BMD, whereas another study reported a decrease in total body and spine BMD, but only with the use of phenytoin for > 2 years. With phenytoin combined with a ketogenic diet, a decrease in forearm BMC was seen. For phenobarbital, one study showed a decrease in spine and total body BMD, but only among those who had used phenobarbital for > 2 years. Six studies were available for carbamazepine, and none of these showed a decrease in BMD in any skeletal site. For valproate, results were diverse; two studies reported a decrease in spine BMD, whereas two other studies did not. Two studies reported a decrease in hip BMD with valproate, whereas one did not. All three studies on forearm BMD in users of valproate described a decrease. Three studies reported an improvement in BMC with vitamin D supplementation in children on AEDs. No reports on changes in BMD among users of newer AEDs are available. In conclusion, more evidence is needed for the effects on BMD in children, especially for newer AEDs. The available studies have all been cross-sectional, and longitudianal studies are needed along with studies on potential interventions in children with decreased BMD.

Effects of anticonvulsant therapy on vitamin D status in children: prospective monitoring study

Reports of hypovitaminosis D associated with anticonvulsant drugs in pediatric patients are conflicting. The effects of carbamazepine or sodium valproate on vitamin D status were evaluated prospectively in 51 ambulatory epileptic children who were followed during the first year of the study and in 25 and 6 children during the second and third year, respectively. Serum 25-hydroxyvitamin D, parathyroid hormone, calcium, and phosphorus levels were determined before and every 3 months during anticonvulsant therapy. Our subjects were grouped into four classes (0, 1, 2, and 3 consisted of the patients before and during the first, second, and third years of the treatment, respectively). The control group consisted of 80 healthy children. Comparisons between controls and patients of class 0 for the means for each season of all variables showed no significant differences. A decreasing trend in serum 25-hydroxyvitamin D (P < .03) and an increasing trend in serum parathyroid hormone (P < .04) levels were noticed in all seasons from class 0 to class 3. Twenty-five patients (49%) acquired hypovitaminosis D during the study period. The effects of seasonality on serum 25-hydroxyvitamin D, parathyroid hormone, and calcium were noticed in our patients grouped in classes 0, 2 and 3, as well as in controls. Evidence is provided that carbamazepine or sodium valproate can cause hypovitaminosis D in children.

Osteoporosis in children and adolescents: etiology and management

Bone mass increases progressively during childhood, but mainly during adolescence when approximately 40% of total bone mass is accumulated. Peak bone mass is reached in late adolescence, and is a well recognised risk factor for osteoporosis later in life. Thus, increasing peak bone mass can prevent osteoporosis. The critical interpretation of bone mass measurements is a crucial factor for the diagnosis of osteopenia/osteoporosis in children and adolescents. To date, there are insufficient data to formally define osteopenia/osteoporosis in this patient group, and the guidelines used for adult patients are not applicable. In males and females aged <20 years the terminology 'low bone density for chronologic age' may be used if the Z-score is less than -2. For children and adolescents, this terminology is more appropriate than osteopenia/osteoporosis. Moreover, the T-score should not be used in children and adolescents. Many disorders, by various mechanisms, may affect the acquisition of bone mass during childhood and adolescence. Indeed, the number of disorders that have been identified as affecting bone mass in this age group is increasing as a consequence of the wide use of bone mass measurements. The increased survival of children and adolescents with chronic diseases or malignancies, as well as the use of some treatment regimens has resulted in an increase in the incidence of reduced bone mass in this age group. Experience in treating the various disorders associated with osteoporosis in childhood is limited at present. The first approach to osteoporosis management in children and adolescents should be aimed at treating the underlying disease. The use of bisphosphonates in children and adolescents with osteoporosis is increasing and their positive effect in improving bone mineral density is encouraging. Osteoporosis prevention is a key factor and it should begin in childhood. Pediatricians should have a fundamental role in the prevention of osteoporosis, suggesting strategies to achieve an optimal peak bone mass.

Epilepsy, osteoporosis and fracture risk - a meta-analysis

This meta-analysis assesses the effects of epilepsy on fracture risk and changes in bone mineral density (BMD) in patients with epilepsy. A search of PubMed was conducted using the key words epilepsy, fracture, and bone mineral. A weighted estimate of relative risk of fractures and changes in BMD (Z-score) was calculated. From the changes in BMD, expected increase in relative fracture risk was calculated. A total of 11 studies on fracture risk and 12 studies on BMD were retrieved. The relative risk of any fracture was increased (2.2, 95% CI: 1.9-2.5, five studies), as was the risk of hip (5.3, 3.2-8.8, six studies), forearm (1.7, 1.2-2.3, six studies), and spine fractures (6.2, 2.5-15.5, three studies). A large proportion of fractures (35%) seemed related to seizures. Spine (mean +/- SEM: -0.38 +/- 0.06) and hip (-0.56 +/- 0.06) BMD Z-scores were significantly decreased, hip more than spine (2P < 0.05). The expected increases in relative risk of any fracture from BMD Z-scores were 1.2-1.3, and significantly lower than observed (2P < 0.05). The deficit in BMD in patients with epilepsy is too small to explain the observed increase in fracture risk. The remainder of the increase in fracture risk may be linked to seizures.

Epidemiology of fractures in people with severe and profound developmental disabilities

Fractures are more prevalent among people with severe and profound developmental disabilities than in the general population. In order to characterize the tendency of these people to fracture, and to identify features that may guide the development of preventive strategies, we analyzed fracture epidemiology in people with severe and profound developmental disabilities who lived in a stable environment. Data from a 23-year longitudinal cohort registry of 1434 people with severe and profound developmental disabilities were analyzed to determine the effects of age, gender, mobility, bone fractured, month of fracture, and fracture history upon fracture rates. Eighty-five percent of all fractures involved the extremities. The overall fracture rate increased as mobility increased. In contrast, femoral shaft fracture risk was substantially higher in the least mobile [relative risk (RR), 10.36; 95% confidence interval (CI), 3.29-32.66] compared with the most mobile group. Although the overall fracture rate was not associated with age, the femoral shaft fractures decreased but hand/foot fractures increased with age. Overall fracture risk declined in August and September (RR, 0.70; 95% CI, 0.55-0.89), being especially prominent for tibial/fibular fractures (RR, 0.31; 95% CI, 0.13-0.70). Gender was not a factor in fracture risk. Two primary fracture mechanisms are apparent: one, largely associated with lack of weight-bearing in people with the least mobility, is exemplified by femoral fractures during non-traumatic events as simple as diapering or transfers; the other, probably due to movement- or fall-related trauma, is exemplified by hand/foot fractures in people who ambulate. The fracture experience of people with severe and profound developmental disabilities is unique and, because it differs qualitatively from postmenopausal osteoporosis, may require population-specific methods for assessing risk, for improving bone integrity, and for reduction of falls and accidents.

Antiepileptic drugs and reduced bone mineral density

There is a growing interest in recognizing the association between antiepileptic drugs and reduced bone mineral density. Although the literature regarding this association has been available for more than three decades, the management of this complication remains unclear. We review the relevant literature regarding antiepileptic drugs and reduction in bone mineral density with the aim of developing some guidelines for practical management of this problem. This review focuses on the mechanism of antiepileptic drug-induced bone loss, its recognition, and its management.

Increased bone turnover in prepubertal, pubertal, and postpubertal patients receiving carbamazepine

PURPOSE

To study the markers of bone turnover in epilepsy patients in the different stages of the pubertal growth before and after the beginning of carbamazepine (CBZ) monotherapy.

METHODS

We have investigated bone turnover in 60 epilepsy patients treated with CBZ. They were stratified according to pubertal stage and compared with a control group of 60 sex- and age-matched healthy children.

RESULTS

After 2 years of therapy, we found higher values of the serum markers of bone formation [bone alkaline phosphatase (bone ALP), osteocalcin (OC), carboxy-terminal propeptide of type I procollagen (PICP), amino-terminal propeptide of type III procollagen (PIIINP)], and of bone resorption [carboxy-terminal telopeptide of type I collagen (ICTP) and the urinary cross-linked N-telopeptides of type I collagen (NTX)] in patients than in control subjects, in presence of a normal vitamin D metabolism.

CONCLUSIONS

CBZ induces an increase of bone formation and of bone resorption that seems to be independent of the pubertal stage.

Adverse effects of antiepileptic drugs on bone structure: epidemiology, mechanisms and therapeutic implications

Antiepileptic drugs (AEDs) were first associated with disorders of bone in both adults and children in the late 1960s. The most severe manifestations of these disorders are osteopenia/osteoporosis, osteomalacia and fractures. Bone disease has been described in several groups of patients receiving AEDs. Groups identified as being more vulnerable to AED-associated bone disease include institutionalised patients, postmenopausal women, older men and children. Radiological and histological evidence of bone disease is found in patients taking AEDs. Numerous biochemical abnormalities of bone metabolism have also been described. The severity of bone and biochemical abnormalities is thought to correlate with the duration of AED exposure and the number of AEDs used. In monotherapy, the AEDs most commonly associated with altered bone metabolism are phenytoin, primidone and phenobarbital (phenobarbitone). To date there have been no reports of altered bone metabolism in individuals receiving the newer anticonvulsants (specifically lamotrigine, topiramate, vigabatrin and gabapentin). The mechanisms of AED-associated bone disease are not clearly elucidated; however, several theories have been proposed to explain the link. No definitive guidelines for evaluation or treatment have yet been determined.

Effect of antiepileptic drugs on bone mineral density in children between ages 6 and 12 years

We assessed the effects of sodium valproate and carbamazepine monotherapy on bone mineral density (BMD) in children. BMD at the lumbar vertebrae (L1-L4) and radius-ulna was measured by the dual-energy x-ray absorptiometry (DEXA) method in 19 children (9 girls, 10 boys) with uncomplicated epilepsy and in 57 healthy children (28 girls, 29 boys), between the ages of 6 and 12 years. The study patients had been receiving either sodium valproate (n = 13) or carbamazepine (n = 6) monotherapy for more than 6 months. There were no significant differences between the control and study patients in age, height, weight, physical activity, or of serum concentrations of calcium, phosphate, and transaminases (aspartate aminotransferase, alanine aminotransferase). However, the serum alkaline phosphatase concentration was greater in the patient group as compared with the control group. BMD values were lower in girl patients (L1-L4; 0.497 +/- 0.08 vs 0.566 +/- 0.07 g/cm2, p < 0.05), but not in boys (0.534 +/- 0.06 vs 0.530 +/- 0.08 g/cm2). While BMD reduction was 8% in valproate therapy (midregion of radius-ulna; 0.287 +/- 0.03 vs 0.312 +/- 0.04 g/cm2, p < 0.04), it was reduced only 4.5% in the carbamazepine-treated group (0.298 +/- 0.01 vs 0.312 +/- 0.04 g/cm2, statistically not significant), although the mean durations of monotherapy with valproate (1.8 +/- 0.7 years) and carbamazepine (1.7 +/- 0.8 years) were similar. Thus decreased bone mineralization was observed in children with epilepsy, treated with sodium valproate even though treatment was for a rather short time.

Vitamin D levels in noninstitutionalized children with cerebral palsy

Calcitriol (1,25-dihydroxy vitamin D) is an important hormone in calcium and phosphate metabolism. Levels of calcitriol and its precursor, 25-hydroxy vitamin D (calcidiol), were measured in a heterogeneous group of 125 noninstitutionalized children and adolescents with spastic cerebral palsy. Levels of each were correlated with: (1) clinical factors including mobility, prior fracture, and use of anticonvulsants; (2) nutrition and growth parameters including skinfolds, body mass index, and use of vitamin supplements; and (3) other serum analyses including osteocalcin as a marker of bone formation, calcium, and alkaline phosphatase. Levels of calcidiol and calcitriol did not correlate with any of the various clinical, nutritional, or growth parameters examined. The prevalence of low (< 10 ng/mL) levels of calcidiol was significant (19%), and dependent on the season of the year in which the level was measured. In contrast, less than 2% of the patients were found to have a low (< 20 pg/mL) level of calcitriol and the mean was comparable to normal pediatric subjects. Levels of calcitriol are maintained in noninstitutionalized children with cerebral palsy despite anticonvulsants, poor nutrition, and calcidiol levels that vary greatly with the seasons.

Bone-mineral density in children and adolescents who have spastic cerebral palsy

Bone-mineral density was studied in a heterogeneous group of 139 children (mean age, nine years; range, three to fifteen years) who had spastic cerebral palsy. The evaluation included serum analyses and a nutritional assessment based on a dietary history and anthropometric measurements. The bone-mineral density of the proximal parts of the femora and the lumbar spine was measured with dual-energy x-ray absorptiometry and was normalized for age against a series of ninety-five normal children and adolescents who served as controls. Bone-mineral density varied greatly but averaged nearly one standard deviation below the age-matched normal means for both the proximal parts of the femora (-0.92 standard deviation) and the lumbar spine (-0.80 standard deviation). Ambulatory status was the factor that best correlated with bone-mineral density. Nutritional status, assessed on the basis of caloric intake, skinfolds, and body-mass index, was the second most significant variable. The pattern of involvement, durations of immobilization in a cast, and a calcium intake of less than 500 milligrams per day were additional factors of less significance. The age when the child first walked, previous fractures, use of anticonvulsants, and serum vitamin-D levels did not correlate with bone-mineral density after adjustment for covariance with the ambulatory status and the nutritional status. Serum levels of calcium, phosphate, alkaline phosphatase, and osteocalcin were not reliable indicators of low bone-mineral density.

Bone mineral density measured by dual-energy x-ray absorptiometry and novel markers of bone formation and resorption in patients on antiepileptic drugs

In patients on antiepileptic drugs, bone loss has been mainly demonstrated at radial sites using old technology and has been ascribed to drug-induced vitamin D deficiency rather than to any direct effects of the treatment on bone cells. We examined 38 epileptic patients (24 women and 14 men) aged 20-49 years who were using either carbamazepine or phenytoin or both. Bone mineral density (BMD) at the lumbar spine and three femoral sites was measured by dual-energy x-ray absorptiometry (DXA) and serum and urine markers of bone and mineral metabolism were determined. The latter included the C-terminal extension peptide of type I procollagen (PICP), a putative serum marker of bone formation, and the cross-linked carboxyl-terminal telopeptide of human type I collagen (ICTP), a novel serum marker of bone matrix degradation. In female patients on phenytoin, weight- and height-adjusted BMD was reduced at the femoral neck and the Ward's triangle (p < 0.05) but was at the control level in the other patient groups at all four measurement sites. Compared with controls, the serum concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were reduced by 26% (p < 0.01) and by 27% (p < 0.001) in female patients. These changes were independent of the therapy used. They were not present in male patients. For both genders the serum levels of vitamin D binding protein were normal. Both female and male patients had hypocalcemia, but women only showed hypocalciuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary fiber and long-term large bowel response in enterally nourished nonambulatory profoundly retarded youth

The objective of this year-long research was to determine the effects of three levels of a purified dietary fiber source, soy polysaccharide, on the long-term bowel function of 11 youth, aged 7 to 17 years, who were nonambulatory, profoundly disabled, constipated, and fed by gastrostomy. From day 1 to 60 the diet was a fiber-free enteral feeding; from day 61 to 300, 12 to 20 g/day total fiber was added to the diet; and from day 301 to 360, 18 to 25 g/day. Complete stool collections were made from day 51 to 60, day 111 to 120, day 291 to 300, day 321 to 330, and day 351 to 360. The second fiber addition significantly increased mean (+/- SD) daily stool frequency from 0.6 +/- 0.2 during the fiber-free diet to 1.1 +/- 0.5. The first addition of fiber compared to the fiber-free diet significantly increased stool moisture from 70 +/- 7% to 76 +/- 8% and wet stool weight from 30 +/- 13 g/day to 53 +/- 21; mean stool weight during days 351 to 360 was 87 +/- 45 g/day. Daily dry stool weight significantly increased with the second fiber addition. Soy polysaccharide fiber improved bowel function in this nonambulatory profoundly disabled population.